The major objectives of these studies are to isolate, characterize and standardize protein components from the human pathogenic organism, Aspergillus fumigatus. These components will then be used to study immunological parameters in patients having Aspergillus related diseases, primarily allergic bronchopulmonary aspergillosis (ABPA), hypersensitivity pneumonitis (HP) and aspergilloma. In addition, these components will be used to study the pathogenesis of ABPA and HP particularly in animal models. The approach taken in this work is to divide the components into three fractions: (a) culture filtrate (CF), (b) cell sap (CS) and (c) cell wall/membrane complex (CW/M). The CF is obtained by centrifugation of the mycelial growth. CS is obtained by homogenization of the mycelial mat and subsequent centrifugation of the insoluble debris which represents the CW/M complex. Fractionation of the CF and CS is carried out by standard protein separation procedures. Immunological parameters tested with these components include: (a) serum antibody, (b) lymphocyte transformation and (c) skin testing. The CW/M complex is being investigated by extraction procedures in various detergents and denaturants. The amount of protein extracted by these procedures is then quantitated by the O-phthalaldehyde procedure after hydrolysis. The extracted protein is then studied by 2D polyacrylamide gel electrophoresis. The extracts will be fractionated by procedures such as gel filtration in the presence of 6 M guanidine hydrochloride and isoelectric focusing in the presence of urea.